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F. RAHM Sept. 17, 1929 PUMP Filed Deo. 19. 1927 Patented Sept. 17, 1929 UNITED STA'MES PATENT FFICE.

FREDERICH RAHM, OF LOUSVILLE, KENTUCKY, ASSIGNOB, TO PBIECSON SYRU'P PUMP COMPANY, 0F LOUIS-VILLE, KENTUCKY, A CORPOBATEON UF DELAKARE PUMF Application filed December 19, 1927. Serial No. 240,985.

My invention relates to pumps for dispensingiT a predetermined quantity oi liquid, and it is of the type known as syrup pumps for soda fountains.

The object oi my invention is to provide a pump which will deliver a definite charge. whether the pump is operated frequently or whether the charge is dispensed after a lapse of a few hours.

Another object of the invention is to provide a pump which will minimize the delivery oi' froth, aud compensate for irregularities in working parts, generally present in the containers from which the pump delivers.

A still further object of the invention is to provide a pump of the character described, in which the quantity to be discharged by the pump can be adjusted b v Changing the setting wit-hout in any way aifecting the piston displacement.

In the appended drawing forming part of this application, Figure 1 is a vertical section on line 1 1, Figure 3 et a pump embodying my invention.

Figure 2 is a similar section on line 2 2, Figure 3, the upper portion of the pump not being shown.

Figure 3 is a section on line 3 3. Figure 1.

Figure 4 is a plan View ot the cylinder and the valve housings., and Figure 5 is a section through the valve housings ot the cylinders on line Figure 3, the valves being eliminated from the drawing to better illus- V trate the structure.

Referring to the drawing, 10 is the cylinf der open at the bottom. A piston 11 fitting into the cylinder has its piston rod 12 pro- .iecting through the cylinder top and eXtending into the socket 13 of a header 14. Secured to the piston rod 12 is a button 15 whicn has a sleeve 16 extending into the socket 13 of the header. A spring 17 housed in the sleeve and socket maintains the piston 11 normally against the top of the cylinder, as shown in dash and dot lines in Figures 1 and 2.

The header 14 is provided with a spout 18 connected by a tube 19 to the valve housing 20, wherein a check valve 2l below the tube 19 checks the flow from the spout past the valve.

The valve housing 2O has also a bore 22 which is coaxial with a bore 23 and a bore 24, the bore 24 being larger than 23 and the bore 23 being` larger than 22. The bore 22 has a port 25 leading below the check valve 21. The bore 23 has a port 26 leading to the top et the cylinder. il. plunger 27 is located inthe bore 22. lt has a reduced portion 28 whicl'i terminates with` a plunger 29 that fits the bore A spring 30 is provided on 'the reduced portion 23 between the plunger 29 and the shoulder 31 formed by the bores 22 and 23. This spring normally tends to move the plunger 29 out of the bore 23 and maintain the port 25 closed.

The plunger 27 is adjustably threaded to a head 32 which limits the motion of the plunger-s 27 and 29 by the spring 30. The head 32 carries a trigger 33 which is engageable by a pawl 34 secured to the piston rod 12 to engage the trigger when the piston is at the end ot the suction stroke, which is limited bv the stop collar 35 secured to the rod 12` The pawl 34 is maintained in alignment with the trigger by a guiding groove 36 provided in the stay rod 37 which connects the header' to the cylinder.

`When a charge is to be delivered by the n pump, pressure is applied to the button 15 and the same is moved from the dot and dash position in Figure 1 to the full line position in the same figure, the downward motion of the piston being limited by the stop collar 35. The same motion will cause the pawl 34 to engage the trigger 33. During the downward displacement of the piston, a charge will be taken in through the bores 24 and 23 and port 26. As the piston returns under the iniiuence oit the spring 17, the pawl 34 will carry therewith the trigger 33 and therefore the plungers 27 and 29 compressing the spring 30. It is evident that the spring 17 is stronger than the spring 30.

Until the plunger 29 engages the bore 23, `there will be a discharge from the cylinder through the bores 23 and 24 back into the container :from which the charge has been taken. By the time the plunger 29 engages the bore 23, the plunger 27 starts to uncover the port 25, thereby causing the remainder of the charge to pass toward the spout through the check valve 21.

By permitting a partial return or Waste of the charge to the container, most of the froth that has been taken in is returned to the container and only the liquid Which forms the remaining part of the charge in the cylinder is delivered through the spout. As the piston reaches the top of the cylinder, the trigger 83 is actuated by the projection 38 provided on the valve housing to disengage the same from the pavvl 34. This is shown in dot and dash lines of Fig ure 2. Thus the spring 8O is free to restore the plungers to their normal position; that is to say, the pump is ready for delivering another charge.

In view of the character of the liquid for i Which these pumps are used, it is of advantage to provide in the cylinder annular grooves 37 at suitable intervals, as they help to seal the clearance between the piston and the cylinder Walls and therefore the seepage during the movement of the piston. For the same purpose, a groove 38 is provided in the bore 22 to prevent the liquid stored between the check valve and the plunger 27 from seeping back into the container from which the charges are taken.

I claim:

1. In a pump for delivering a predetermined charge through a passage, means for accumulating a charge larger than the one to be delivered, and means in the passage i'or returning part of said charge at the beginning of the delivery only.

2. In a pump for delivering from a suit able source a predetermined charge through a passage, means for accumulatinga charge larger than the one to be delivered. and means in the passage for returning part ot said charge during the delivery back to the source. f

3. In a pump for delivering from a suitable source a predetermined charge through a passage, means for accumulating a charge larger than the one to he delivered, means in the passage i'or returning part of said charge during the delivery and adjustable means for varying the amount to be returned 4e. In a pump, a cylinder, a spring actuated piston therein, means for returning a part of the charge delivered by the piston, and means for actuating said return controlling means during the delivery stroke of the piston.

5. In a pump, a cylinder, a spring actuated piston therein, a spout leading from the cylinder, a spring actuated plunger valve interposed between the spout and the cylinder and normally closing the passage from the Cylinder to the spout a second plunger valve cooperating With the first 'for controlling the intake of the cylinder and normally maintaining the intake open, means for actuating` the plunger valve during the discharge stroke of the piston, said second plunger maintaining the intake open for a predetermined portion of the piston dis charge stroke and said first plunger maintaining the discharge closed for substantially the same period. y

6. In a pump, a cylinder, a spring actu- -ated piston therein, a spout leading from the cylinder, a spring actuated plunger valve interposed between the spout and the cylinder and normally closing the passage from the cylinder to the spout, a second plunger valve cooperating with the first for controlling the intake of the cylinder and normally maintaining the intake open, a trigger connected to the plunger valves, a pawl movable with the piston for engaging the trigger at the end of the suction stroke, and means for releasing the trigger i'rom the pawl at the end of the discharge stroke, said second plunger maintaining the intake open for a predetermined portion ofA the piston discharge strokeI- and said first plunger maintaining the discharge closed for substantially the same period.

7 In a pump, a cylinder, a spring actuated piston therein, a spout leading from the cylinder, a valve checking the flo-iv from the spout, a spring actuated plunger valve interposed between the check valve and the cylinder andv normally closing the passage from the cylinder to the check valve, a second plunger valve cooperating with the first tor controlling the intake oi the cylinder and normally maintaining the same open, a trigger connected to said plunger valves, a pawl movable with the piston 'for eng the trigger at the end of the suction stroke, means for releasing the trigger from the pavvl at the end of the discharge stroke, said second plunger maintainiimthe intake open for a predetermined portion of the piston discharge stroke and said first plunger maintaining the discharge closed for substantially the same period, and means :for adjustii y, the plunger valves to vary the time ol the operation With reference to the pisto-n discharge stroke.

8. In a pump, a spring actuated piston therein, said cylinder having a passage serving as an intake from a source and a disl charge for the pump, means in said passage making it either an intake or discharge passage, said means being arranged. to return a part of the charge in the cylinder to the source, at the beginning of the delivery stroke of the piston.

` .FEEDER-IGH RHM. 

